Move declarations out of for loops in fmpz_mat/test
Move declarations out of for loops in fmpz_mat/test

jpflori/flint2,dsroche/flint2,fredrik-johansson/flint2,wbhart/flint2,wbhart/flint2,jpflori/flint2,fredrik-johansson/flint2,dsroche/flint2,dsroche/flint2,jpflori/flint2,wbhart/flint2,dsroche/flint2,fredrik-johansson/flint2,jpflori/flint2